Roof construction

ABSTRACT

A flexible roof structure supported by tension members extending in a catenary between the walls of the structure and a second set of tension members interconnected to the first set of tension members through a hold, the tension members of the first set in position and preventing undue flexing of the roof.

United States Patent Mollinger [4 Feb.22 19'72 [54] ROOF CONSTRUCTIUN[72] Inventor: Sebastian Mollinger, 17 Irving Place, Montreal 970.Quebec, Canada [22] Filed: Oct. 3, 1969 [21 Appl. No: 863,584

[52] US. Cl. ..52/83, 52/222 [51] 1nt.Cl ..E04b 7/14 [58]lFieldotSem-cli .52/83,63, 222

[56] References Cited UNITED STATES PATENTS 1,109,399 9/1914 Butler..52/83 1,481,019 1/1924 Luebbert ..52/83 1,825,800 10/1931 Houseman..52/83 X 3,410,039 11/1968 Brezina ..52/83 X Primary Examiner--Frank L.Abbott Assistant ExaminerSam D. Burke- Attomey-Alan Swabey ABSTRACT Aflexible roof structure supported by tension members extending in acatenary between the walls of the structure and a second set of tensionmembers interconnected to the first set of tension members through ahold, the tension members of the first set in position and preventingundue flexing of the roof.

8 Claims, 6 Drawing Figunes ELBAPHBQI;

MWWFEB 22 m2 SHEET 0F 3 INVENTOR mbumiiun MOLLENGER A TTORNEY ROOFCONSTRUCTION BACKGROUND OF THE INVENTION 1. Field of the Invention Thepresent invention relates to roofs. More specifically, the presentinvention relates to roof structures employing flexible roof skins andsuitable for buildings having relatively long unsupported spans ofsquare or rectangular roof areas.

2. Description of the Prior Art It is a practice in the constructionindustry to build roofs for large buildings using rigid or semirigidroof decking supported on substantially rigid purlins which, in turn,are supported on trusses that may consist of top and bottom chords,struts, diagonals, etc. Such roofs are relatively expensive.

Roofs employing flexible skins have found only very limited use and havegenerally been reserved for relatively small structures or very unusualstructures. For a roof of any reasonable size to be made using flexibleskins, i.e., on tents or the like, it is a practice to stretch theflexible skin under tension and provide an abrupt change in directionfor a slope in the roof to improve the rigidity of the structure andreduce the tendency for it to flutter in the wind.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a relatively inexpensive roof structure for covering largeunsupported spans.

A further object of the present invention is to provide a suspended roofstructure specially adapted for large unsupported spans and utilizingflexible roofing skins.

Broadly, the present invention comprises means defining a roof opening,a first set consisting of a plurality of spaced, substantially parallel,elongated flexible tension members spanning the roof opening, flexibleroofing skins, means connecting said flexible roofing skins to saidfirst set of flexible tension members, a second set consisting of aplurality of spaced, substantially parallel tension members, spacingmembers extending transversely of said first set of tension members formaintaining said tension members in spaced-apart relationship, aplurality of spaced force-transmitting means connecting said tensionmembers of said first set with said tension members of said second set,said tension members of said first set applying a force to saidforce-transmitting means in one direction while said tension members ofsaid second set apply a force in substantially the opposite direction,whereby movement of said tension members of said first set is resistedby said tension members of said second set.

BRIEF DESCRIPTION OF THE INVENTION Further features, objects andadvantages will be evident from the following detailed description of apreferred embodiment of the present invention taken in conjunction withthe accompanying drawings in which:

FIG. 1 is an isometric schematic view illustrating a preferred form ofthe present invention;

FIG. 2 is a schematic view ofa detail ofFIG. 1;

FIG. 3 is a section of one form of connector for mounting the skin andcatwalk on the roof structure;

FIGS. 4, 5 and 6 are isometric views similar to FIG. 1 but illustratingmodifications of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, thestructure 10 is composed of four vertical walls 12, I4, 16 and 18 withconventional vertical columns which may, if desired, be stayed inposition by fixing, bracing or guying them to the foundations.

In the illustrated arrangement, a first set of cables or the liketension members 20 are anchored to the opposite columns of walls 14 and18 of the structure 10 and extend in a catenary therebetween. A secondset of cables or tension members 22 are anchored in a manner to bedescribed hereinbelow to the opposite walls 12 and 16 and extend inoverlying relationship to the members 20. Between the members 20 aresupporting members in the form of cables or the like 24 extending as acatenary between adjacent members 20 and functioning to support theflexible roof skins 26 (see FIG. 3).

As indicated above, the second set of cables 22 extends over the cables20. Spaced-apart secondary compression members 28 arranged in rows inalignment with the second set of tension members or cables 22 project upfrom each of the tension members 20 and connect the members 20 and 22and function to transfer forces between the tension: members 20 and 22.These compression members 28 are held in substantially vertical positionby means of tie or tension wires 30 connected to the members 20. In theillustrated embodiment, a substantially rigid catwalk 32 is connected tothe tension members 20 adjacent the center of the roof span or catenaryformed by the members 20. The specific mounting means for the catwalk 32and for the compression members 28 and how they are connected to themember 20 will be described in more detail with reference to FIGS. 2 and3. A rigid spacer 34 extends between the compression members 28 in eachrow of compression members 28 located on opposite sides of thecenterline of the roof. The catwalk 32 and spacing members 34 functionto maintain the lateral spacing of the members 28 and thus of thetension members 20.

The ends of the second set of tension members 22 are connected to thewalls 12 and 16 in a specific manner. As shown, the end cables indicatedat 21 of the first set of tension members 20 are anchored at oppositeends to the walls 14 and 18. Also anchored to the walls 14 and 18beneath the top thereof is a secondary tension member 36. This member 36is connected to structural members 38 forming part of the wall 12. Toeach of the members 38 is connected the end of a tension member 22 ofthe second set of tension members and projecting downwardly and inwardlyfrom each of the members 38 is a compression member 40. The oppositeends of the compression members 40 are supported from a tension member20 by a suitable cable or the like 42. A cable or supporting tensionmember 44 is anchored to the cornerposts of the structure 10 and isconnected to the compression members 40. The support members 40 extendto a point below catenaries 20 and are attached thereto by a verticaltension member 4l2. The horizontal inward component of a force comingfrom cable polygons 22 or catwalk 32 or spacers 34 or catenary 20 istransmitted via the compression members 40 to tension member 44 and tothe comerposts of the structure 10.

Referring to FIGS. 2 and 3, as can be seen, each compression member 28is clamped to and projects upwardly from the cables 20 and is supportedin a vertical position by means of the tension wires 30 which areconnected to the cables 20 by suitable clamps. Each of the clamps forholding the catwalk 32, compression members 28 or tension wires 30 isformed by a steel strap or the like 50 which encircles the cable 20 andis clamped thereto by a bolt 52 (see FIG. 3) which bolt 52 alsofunctions to support a hanger 53 for a drainpipe 54 (see FIG. 2). Thedrainpipe 54 is connected by a standpipe to the lowest part of the roofand functions to drain the water that tends to accumulate here. A studS6 is welded or otherwise secured to the clamp strap 50 and projectsupwardly therefrom. The stud 56 receives a rubber washer 58, flexibleroof skin 26, a second rubber washer 60 and a rigid washer 62 or thelike. If the clamp is not to support the catwalk 32, then the skin 26may simply be clamped between the two washers 58 and 60 by means of asuitable bolt and if a tie 30 is to be connected at the clamp, it may beconnected to the stud 56 above the abovementioned clamping bolt.

When the clamp is to support the catwalk 32, the stud 56 is preferablyextended as shown in FIG. 3 and a horizontal frame member 64 having apair of spaced hollow elements or pipes 66 is positioned so that eachpipe 66 receives a stud 56 projecting from a pair of spaced clamps andis bolted into position by suitable bolts 68 (only one shown).Tightening of the bolts 68 moves the frame member 64 and pipe 66 downagainst the washer 62 to clamp the skin 26 between the rubber washers 58and 60. The catwalk 32 may be secured to the structural member 64 in anysuitable manner. As above indicated, the catwalk is a substantially rigid structure that maintains the spacing between the tension members 20.

The compression members 28 may take the form of simple standpipes thattelescope over the ends of the stud 56, thereby mounting the compressionmembers 28 in position.

In operation, the tension members 20 are held in position by thecombined action of the spacer 34 and catwalk 32 maintaining the spacingof the members 20 and the tension members 22 which extend in the form ofa polygon and force the members 20 downwardly through pressure appliedbetween the members 20 and 22 by the compression members 28. Thus, ifthe wind tends to cause ripples or waves in the flexible skin 26, i.e.,to lift the skin 26 and thus the whole roof, the tension members 22acting through compression members 2 prevent the roof from lifting.

The tension members 36 and the members 38 combine with the cables 44 andsecondary compression members 40 to maintain the tension members 22 inproper position and resist the stresses applied to the end wall 12 bythe members 22. This structure employing the tension members 36 and 44reduces the structural rigidity required in the walls 12 and 16 tosupport the cables 22. The walls 12 and 16 may be made sufficientlyrigid to support the cables; however, since these cables 22 may extendfor an even longer span than the cables 20, the walls 12 and 18 ifconventionally constructed would have to be exceptionally heavy.

In the arrangement shown in FIG. 4, the second set of cables 22 has beenreplaced by anotherset of cables 22' which extend between the walls 14and 18 and are anchored thereto at a position directly below each of thecables 20. The tension members or cables 22' are connected at spacedlocations to the cables 20 immediately thereabove by suitable tensionmembers 70 which may, for convenience, include tumbuckles to adjust thelength and to ensure that the cables 20 and 22' are tightly securedtogether. in this arrangement, the catwalk 32 and spacers 36 for thecables 20 are retained. However, obviously, the compression members 28and their ties 30 may be dispensed with.

In the operation of the H6. 4 embodiment, movement of the cables 20 and22' is mutually restricted by each pair of cables 20 and 22 pullingagainst the other through the tension members 70.

' In the arrangement of FIG. 5, the second set of cables 22 has beenreplaced by a set of cables 22" which extend sub stantially parallel tothe cables 20 but instead of being below the cables 20 as were thecables 22', the cables 22" are above. The cables 22" are connected tothe cables 20 by suitable compression members 28' that are guyed by guywires 30' to the spacer members 34 and catwalk 32 rather than to thecables 20 as were the compression members 28 of the FIG. 1 embodiments.

In the operation of the FIG. arrangement, the cables 22" hold the cablesdown much in the manner the cables 22 operate in the H0. 1 embodiment.

Modifications may be made to the invention as disclosed and combinationsof the various arrangements of cables may be used, i.e., the cables 22may be used together with the cables 22 or cables 22" to hold down thecables 20 or both cables 22' and 22" may be used with cables 20 or someof each may be used.

One arrangement incorporating cables similar to cables 22" and 22 isillustrated in H6. 6. Compression members 28" space the cables 22, 22'from the cables 20 but do not require guy wires to hold them in place,since they are automatically held in place by the crossing arrangementof the cables 22 and 22". The cables 22" and the compression members 28"at the ends of the structure are held in position by means of rigidmembers 29 which extend from the compression members 28" to the catwalk32 or spacers 34. In the illustrated arrangement, these members 29extend to the adjacent compression members 29".

In operation, the compression members, as indicated, are

maintained in vertical position by the crossing arrangement of thecables 22" and 22 and the end compression members 28" are held invertical position by the rigid members 29. The cables 22, 22 function inthe manner described above to hold the cables 20 in position.

Modifications may be made without departing from the spirit of theinvention as defined in the appended claims.

I claim:

1. A roof structure comprising:

a first set of spaced, substantially parallel tension members forsupporting vertical downward loads,

a second set of spaced, substantially parallel tension members disposedabove and transverse to said first set for supporting vertical upwardwindloads,

flexible roofing skins supported by said first set of tension members,

spacing means traversing said first set of tension members to maintainsaid tension members of said first set at laterally spaced relationship,

a plurality of spaced force-transmitting compression members arranged inrows substantially in alignment with said tension members of said secondset, and 1 said force-transmitting compression members interconnectingsaid tension members of said first and said second sets at spacedlocations.

2. A roof structure as defined in claim 1, wherein said tension membersof said first set extend substantially perpendicular to said tensionmembers of said second set.

3. A roof structure as defined in claim 2, further comprising:

a secondary tension member,

structural members,

said secondary tension member interconnecting said structural members,

said tension members of said second set being connected to saidstructural members,

compression support members connected at one end to a respective one ofsaid structural members and being supported at its other end by asupporting tension member secured to a tension member of said first set,and supporting tension members anchored to corner structural members andto said compression members and supported below the plane of said firstset of tension members.

4. A roof structure as defined in claim 3, wherein said spacing meansincludes a catwalk.

5. A roof structure as defined in claim 1, wherein said tension membersof said first set extend in substantially the same direction as thetension members of said second set.

6. A roof structure as defined in claim 5, further comprising:

a secondary tension member,

structural members,

said secondary tension member interconnecting said structural members,

said tension members of said second set being connected to saidstructural members,

a supporting tension member, and

compression members interconnecting said supporting tension member andsaid structural members.

7. A roof structure as defined in claim 6, wherein said spacing meansincludes a catwalk.

8. A roof structure as defined in claim 1 wherein said second set oftension members extends across opposed structural walls of said roofstructure and are held above and transverse to said first set of tensionmembers at each intersection with a tension member of said first set,said tension members of said second set being held transverse to saidfirst set of tension members a predetermined distance above each tensionmember of said first set and disposed substantially in the form of apolygon.

1. A roof structure comprising: a first set of spaced, substantiallyparallel tension members for supporting vertical downward loads, asecond set of spaced, substantially parallel tension members disposedabove and transverse to said first set for supporting vertical upwardwindloads, flexible roofing skins supported by said first set of tensionmembers, spacing means traversing said first set of tension members tomaintain said tension members of said first set at laterally spacedrelationship, a plurality of spaced force-transmitting compressionmembers arranged in rows substantially in alignment with said tensionmembers of said second set, and said force-transmitting compressionmembers interconnecting said tension members of said first and saidsecond sets at spaced locations.
 2. A roof structure as defined in claim1, wherein said tension members of said first set extend substantiallyperpendicular to said tension members of said second set.
 3. A roofstructure as defined in claim 2, further comprising: a secondary tensionmember, structural members, said secondary tension memberinterconnecting said structural members, said tension members of saidsecond set being connected to said structural members, compressionsupport members connected at one end to a respective one of saidstructural members and being supported at its other end by a supportingtension member secured to a tension member of said first set, andsupporting tension members anchored to corner structural members and tosaid compression members and supported below the plane of said first setof tension members.
 4. A roof structure as defined in claim 3, whereinsaid spacing means includes a catwalk.
 5. A roof structure as defined inclaim 1, wherein said tension members of said first set extend insubstantially the same direction as the tension members of said secondset.
 6. A roof structure as defined in claim 5, further comprising: asecondary tension member, structural members, said secondary tensionmember interconnecting said structural members, said tension members ofsaid second set being connected to said structural members, a supportingtension member, and compression members interconnecting said supportingtension member and said structural members.
 7. A roof structure asdefined in claim 6, wherein said spacing means includes a catwalk.
 8. Aroof structure as defined in claim 1 wherein said second set of tensIonmembers extends across opposed structural walls of said roof structureand are held above and transverse to said first set of tension membersat each intersection with a tension member of said first set, saidtension members of said second set being held transverse to said firstset of tension members a predetermined distance above each tensionmember of said first set and disposed substantially in the form of apolygon.